1. Field of the Invention
The present invention is related to development of Web sites and applications. More specifically, the present invention relates to facilitated communications between a client-side and a server-side.
2. Description of the Related Art
Prior to Rich Internet Applications, traditional Web applications involved a client-server architecture with all of the processing on the server side and the client-side used to display the HTML web-pages served by the server. Each time a user desired to view a new Web-page, a HTTP request was sent to the server and the requested Web-page was served to the Web browser on the client-side. Such a traditional system is shown in FIG. 1 with a Web-server 1000 on a server side receiving requests over the Internet 1005 from a Web-browser 1003 on a client-side.
Rich Internet Applications, such as Ajax, greatly improved on the traditional client-server architecture by allowing the client machine to dynamically render and partially refresh web pages based on an initial set of instructions from the server, user input, and small amounts of subsequent data dynamically requested from the server. As shown in FIG. 2, the client machine processes Ajax instructions to render a Web page for the user.
Early Web applications allowed a user's browser to send a request to a server. The server processed the request and responded to the browser with a Web page. When the user wanted to view a new page, another request was sent to the server and the server responded to the browser with a new Web page. Such a process resulted in a waste of bandwidth since much of the Web contents in the first Web page were also contained in the second web page. The need to resend the same information led to a much slower user interface of a Web application than that of a native application.
An emerging technology, called Ajax (Asynchronous and JavaScript XML), was developed for refreshing part of a page instead of refreshing the whole page on every interaction between the user and application. In an Ajax application, when a user submits a form in a page, a script program, usually a JavaScript program, resident on the Web browser receives the user's request and sends a XML (Extended Markup Language) HTTP (Hyper Text Transfer Protocol) request to the Web server in background so as to retrieve only the needed Web contents instead of the whole page and perform corresponding processing to partly refresh the page when receiving a response from the Web server. In this way, the application response time is shortened, because the amount of data exchanged between the Web browser and the Web server is greatly reduced. And the processing time of the Web server is saved because much of the processing is performed at the client side.
General definitions for terms utilized in the pertinent art are set forth below.
Ajax is the use of dynamic HTML, JavaScript and CSS to create dynamic and usually interactive Web sites and applications. A more detailed explanation of Ajax is set forth in Edmond Woychowsky, AJAX, Creating Web Pages with Asynchronous JavaScript and XML, Prentice Hall, 2007, which is hereby incorporated by reference in its entirety.
Applets or Java Applets are mini-executable programs named with the .class suffix and are placed on a Web page and provide interactive and multimedia uses.
Application Programming Interface (API) is a collection of computer software code, usually a set of class definitions, that can perform a set of related complex tasks, but has a limited set of controls that may be manipulated by other software-code entities. The set of controls is deliberately limited for the sake of clarity and ease of use, so that programmers do not have to work with the detail contained within the given API itself.
An Attribute provides additional information about an element, object or file. In a Document Object Model, an attribute, or attribute node, is contained within an element node.
Behavioral layer is the top layer and is the scripting and programming that adds interactivity and dynamic effects to a site.
Binding in a general sense is the linking of a library to an application program usually to prevent repetition of frequently utilized code.
Cascading Style Sheets (CSS) is a W3C standard for defining the presentation of Web documents.
Compiler is a computer program that translates a series of instructions written in one computer language into a resulting output in a different computer language.
Document Object Model (DOM) Element is an object contained in a Document Object Model (DOM). The term DOM is generally used to refer to the particular DOM held in the memory region being used by the Web browser. Such a DOM controls the Graphical Respondent Interface (GRI) or Graphical User Interface (GUI). The DOM is generated according to the information that the Web browser reads from the HTML file, and/or from direct JavaScript software instructions. Generally, there exists a unique DOM element for every unique HTML element. DOM elements are sometimes referred to as HTML/DOM elements, because the DOM element exists only because HTML code that was read by the Web browser listed some HTML element that had not previously existed, and thereby caused the Web browser to create that DOM element. Often specific elements of the greater set of HTML/DOM elements are identified by specifying an HTML/DOM checkbox element, or an HTML/DOM text input element. A more detailed explanation of the document object model is set forth in Jeremy Keith, DOM Scripting, Web Design with JavaScript and the Document Object Model, friendsof, 2005, which is hereby incorporated by reference in its entirety.
HyperText Markup Language (HTML) is a method of mixing text and other content with layout and appearance commands in a text file, so that a browser can generate a displayed image from the file.
Hypertext Transfer Protocol (HTTP) is a set of conventions for controlling the transfer of information via the Internet from a Web server computer to a client computer, and also from a client computer to a Web server.
Internet is the worldwide, decentralized totality of server computers and data-transmission paths which can supply information to a connected and browser-equipped client computer, and can receive and forward information entered from the client computer.
JavaScript is an object-based programming language. JavaScript is an interpreted language, not a compiled language. JavaScript is generally designed for writing software routines that operate within a client computer on the Internet. Generally, the software routines are downloaded to the client computer at the beginning of the interactive session, if they are not already cached on the client computer. JavaScript is discussed in greater detail below.
JSON is JavaScript Object Notation format, which is a way of taking data and turning it into valid JavaScript syntax for reconstituting an object at the other end of the transmission protocol.
MySQL is a relational database management system which relies on SQL for processing data in a database.
Parser is a component of a compiler that analyzes a sequence of tokens to determine its grammatical structure with respect to a given formal grammer. Parsing transforms input text into a data structure, usually a tree, which is suitable for later processing and which captures the implied hierarchy of the input. XML Parsers ensure that an XML document follows the rules of XML markup syntax correctly.
Platform is the combination of a client computer, an operating system, and a browser, which together can support Internet access and in particular the operation of interactive forms.
Presentation layer follows the structural layer, and provides instructions on how the document should look on the screen, sound when read aloud or be formatted when it is printed.
Rendering engine is software used with a Web browser that takes Web content (HTML, XML, image files) and formatting information (CSS, XSL) and displays the formatted content on a screen.
Serialization places an object in a binary form for transmission across a network such as the Internet and deserialization involves extracting a data structure from a series of bytes.
SQL (Structured Query Language) is a computer language designed for data retrieval and data management in a database.
Structural layer of a Web page is the marked up document and foundation on which other layers may be applied.
User is a client computer, generally operated by a human being, but in some system contexts running an automated process not under full-time human control.
Web-Browser is a complex software program, resident in a client computer, that is capable of loading and displaying text and images and exhibiting behaviors as encoded in HTML (HyperText Markup Language) from the Internet, and also from the client computer's memory. Major browsers include MICROSOFT INTERNET EXPLORER, NETSCAPE, APPLE SAFARI, MOZILLA FIREFOX, and OPERA.
Web-Server is a computer able to simultaneously manage many Internet information-exchange processes at the same time. Normally, server computers are more powerful than client computers, and are administratively and/or geographically centralized. An interactive-form information-collection process generally is controlled from a server computer, to which the sponsor of the process has access.
World Wide Web Consortium (W3C) is an unofficial standards body which creates and oversees the development of web technologies and the application of those technologies.
XHTML (Extensible Hypertext Markup Language) is a language for describing the content of hypertext documents intended to be viewed or read in a browser.
XML (Extensible Markup Language) is a W3C standard for text document markup, and it is not a language but a set of rules for creating other markup languages.
There are three types of JavaScript: 1) Client-side JavaScript; 2) Server-side JavaScript; and 3) Core JavaScript. Client-side JavaScript is generally an extended version of JavaScript that enables the enhancement and manipulation of web pages and client browsers. Server-side JavaScript is an extended version of JavaScript that enables back-end access to databases, file systems, and servers. Core JavaScript is the base JavaScript.
Core JavaScript includes the following objects: array, date, math, number and string. Client-side JavaScript and Server-side JavaScript have additional objects and functions that are specific to client-side or server-side functionality. Generally, any JavaScript libraries (.js files) created in core JavaScript can be used on both the client and the server without changes. Client-side JavaScript is composed of a Core JavaScript and additional objects such as: document, form, frame and window. The objects in Client-side JavaScript enable manipulation of HTML documents (checking form fields, submitting forms, creating dynamic pages) and the browser (directing the browser to load other HTML pages, display messages). Server-side JavaScript is composed of Core JavaScript and additional objects and functions for accessing databases and file systems, and sending email. Server-side JavaScript enables Web developers to efficiently create database-driven web applications. Server-side JavaScript is generally used to create and customize server-based applications by scripting the interaction between objects. Client-side JavaScript may be served by any server but only displayed by JavaScript-enabled browsers. Server-side JavaScript must be served by a JavaScript-enabled server but can be displayed by any browser.
United States Patent Publication Number 20010037359 describes a system and method for a server-side browser including markup language graphical user interface, dynamic markup language rewriter engine and profile engine. The system includes a user computer and a destination server computer separated by a server computer hosting a server-side browser (SSB). The SSB includes a markup language graphical user interface (MLGUI), a dynamic markup language rewriter engine (DMLRE) and a profiling engine (PE). The SSB may be configured as an intermediary infrastructure residing on the Internet providing customized information gathering for a user. The components of the SSB allow for controlling, brokering and distributing information more perfectly by controlling both browser functionality (on the client-side) and server functionality (on the destination site side) within a single point and without the necessity of incremental consents or integration of either side.
Irassar et al., United States Patent Publication Number 20040250262, for Business To Business Event Communications discloses an event handling mechanism that allows communication of event information among providers and subscribers across a network using an event handling server.
Jennings et al., United States Patent Publication Number 20070073739 for a Data-Driven And Plug-In Defined Event Engine, discloses an event engine that enables application developers to define finite state machines for implementation via a data-driven approach using executable plug-ins.
Lindhorst et al., U.S. Pat. No. 6,981,215 for a System For Converting Event-Driven Code Into Serially Executed Code, discloses an event-driven server model that uses active server pages that appear to other files as objects with associated method and properties for developing Web pages.
However, current technologies that operate server-side JavaScript fail to offer complete interactions which are the hallmark of rich web sites and applications. Modern browsers are sophisticated software: they understand multiple versions of HTML, JavaScript, and CSS; they are extremely forgiving of HTML variations, errors, omissions, etc.; they are fast; they parse and execute as they process the incoming stream; and they allow complex, dynamic manipulation of the HTML DOM by JavaScript. To do all this on the server, and to keep doing it well as web technologies and standards evolve, it's best to use a real browser's engine. But browsers are not immediately suitable for use as servers: they do too much client-oriented work that makes little sense for a server that does not interact directly with users, e.g. rendering to a graphical display or handling user events; and they don't do enough server-oriented tasks such as accessing databases and files or selectively executing just the code that should run on the server rather than on the client.
The first thing that must be done is to extract just the engine of the browser, and do so in such a way that the important aspects are preserved: it can evolve as the browser evolves; it can still carry out the basic functionalities needed on the server; etc. Then the engine must be extended to provide the additional server functionalities. But because the engine is usually a highly-optimized program written in a native (platform-specific) language such as C/C++, it is a lot of work to extend it in the same language, and once extended in a certain way, it is a lot of work to change it.